import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:latlong2/latlong.dart';

import 'models/camera_profile.dart';
import 'models/osm_camera_node.dart';
import 'models/pending_upload.dart';
import 'models/tile_provider.dart';
import 'services/offline_area_service.dart';
import 'state/auth_state.dart';
import 'state/profile_state.dart';
import 'state/session_state.dart';
import 'state/settings_state.dart';
import 'state/upload_queue_state.dart';

// Re-export types
export 'state/settings_state.dart' show UploadMode;
export 'state/session_state.dart' show AddCameraSession, EditCameraSession;

// ------------------ AppState ------------------
class AppState extends ChangeNotifier {
  static late AppState instance;
  
  // State modules
  late final AuthState _authState;
  late final ProfileState _profileState;
  late final SessionState _sessionState;
  late final SettingsState _settingsState;
  late final UploadQueueState _uploadQueueState;

  bool _isInitialized = false;

  AppState() {
    instance = this;
    _authState = AuthState();
    _profileState = ProfileState();
    _sessionState = SessionState();
    _settingsState = SettingsState();
    _uploadQueueState = UploadQueueState();
    
    // Set up state change listeners
    _authState.addListener(_onStateChanged);
    _profileState.addListener(_onStateChanged);
    _sessionState.addListener(_onStateChanged);
    _settingsState.addListener(_onStateChanged);
    _uploadQueueState.addListener(_onStateChanged);
    
    _init();
  }

  // Getters that delegate to individual state modules
  bool get isInitialized => _isInitialized;
  
  // Auth state
  bool get isLoggedIn => _authState.isLoggedIn;
  String get username => _authState.username;
  
  // Profile state
  List<CameraProfile> get profiles => _profileState.profiles;
  List<CameraProfile> get enabledProfiles => _profileState.enabledProfiles;
  bool isEnabled(CameraProfile p) => _profileState.isEnabled(p);
  
  // Session state
  AddCameraSession? get session => _sessionState.session;
  EditCameraSession? get editSession => _sessionState.editSession;
  
  // Settings state
  bool get offlineMode => _settingsState.offlineMode;
  int get maxCameras => _settingsState.maxCameras;
  UploadMode get uploadMode => _settingsState.uploadMode;
  
  // Tile provider state
  List<TileProvider> get tileProviders => _settingsState.tileProviders;
  TileType? get selectedTileType => _settingsState.selectedTileType;
  TileProvider? get selectedTileProvider => _settingsState.selectedTileProvider;
  

  
  // Upload queue state
  int get pendingCount => _uploadQueueState.pendingCount;
  List<PendingUpload> get pendingUploads => _uploadQueueState.pendingUploads;

  void _onStateChanged() {
    notifyListeners();
  }

  // ---------- Init ----------
  Future<void> _init() async {
    // Initialize all state modules
    await _settingsState.init();
    await _profileState.init();
    await _uploadQueueState.init();
    await _authState.init(_settingsState.uploadMode);
    
    // Initialize OfflineAreaService to ensure offline areas are loaded
    await OfflineAreaService().ensureInitialized();
    
    // Start uploader if conditions are met
    _startUploader();
    
    _isInitialized = true;
    notifyListeners();
  }

  // ---------- Auth Methods ----------
  Future<void> login() async {
    await _authState.login();
  }

  Future<void> logout() async {
    await _authState.logout();
  }

  Future<void> refreshAuthState() async {
    await _authState.refreshAuthState();
  }

  Future<void> forceLogin() async {
    await _authState.forceLogin();
  }

  Future<bool> validateToken() async {
    return await _authState.validateToken();
  }

  // ---------- Profile Methods ----------
  void toggleProfile(CameraProfile p, bool e) {
    _profileState.toggleProfile(p, e);
  }

  void addOrUpdateProfile(CameraProfile p) {
    _profileState.addOrUpdateProfile(p);
  }

  void deleteProfile(CameraProfile p) {
    _profileState.deleteProfile(p);
  }

  // ---------- Session Methods ----------
  void startAddSession() {
    _sessionState.startAddSession(enabledProfiles);
  }

  void startEditSession(OsmCameraNode node) {
    _sessionState.startEditSession(node, enabledProfiles);
  }

  void updateSession({
    double? directionDeg,
    CameraProfile? profile,
    LatLng? target,
  }) {
    _sessionState.updateSession(
      directionDeg: directionDeg,
      profile: profile,
      target: target,
    );
  }

  void updateEditSession({
    double? directionDeg,
    CameraProfile? profile,
    LatLng? target,
  }) {
    _sessionState.updateEditSession(
      directionDeg: directionDeg,
      profile: profile,
      target: target,
    );
  }

  void cancelSession() {
    _sessionState.cancelSession();
  }

  void cancelEditSession() {
    _sessionState.cancelEditSession();
  }

  void commitSession() {
    final session = _sessionState.commitSession();
    if (session != null) {
      _uploadQueueState.addFromSession(session);
      _startUploader();
    }
  }

  void commitEditSession() {
    final session = _sessionState.commitEditSession();
    if (session != null) {
      _uploadQueueState.addFromEditSession(session);
      _startUploader();
    }
  }

  // ---------- Settings Methods ----------
  Future<void> setOfflineMode(bool enabled) async {
    await _settingsState.setOfflineMode(enabled);
    if (!enabled) {
      _startUploader(); // Resume upload queue processing as we leave offline mode
    } else {
      _uploadQueueState.stopUploader(); // Stop uploader in offline mode
      // Cancel any active area downloads
      await OfflineAreaService().cancelActiveDownloads();
    }
  }

  set maxCameras(int n) {
    _settingsState.maxCameras = n;
  }

  Future<void> setUploadMode(UploadMode mode) async {
    await _settingsState.setUploadMode(mode);
    await _authState.onUploadModeChanged(mode);
    _startUploader(); // Restart uploader with new mode
  }

  /// Select a tile type by ID
  Future<void> setSelectedTileType(String tileTypeId) async {
    await _settingsState.setSelectedTileType(tileTypeId);
  }

  /// Add or update a tile provider
  Future<void> addOrUpdateTileProvider(TileProvider provider) async {
    await _settingsState.addOrUpdateTileProvider(provider);
  }

  /// Delete a tile provider
  Future<void> deleteTileProvider(String providerId) async {
    await _settingsState.deleteTileProvider(providerId);
  }



  // ---------- Queue Methods ----------
  void clearQueue() {
    _uploadQueueState.clearQueue();
  }
  
  void removeFromQueue(PendingUpload upload) {
    _uploadQueueState.removeFromQueue(upload);
  }

  void retryUpload(PendingUpload upload) {
    _uploadQueueState.retryUpload(upload);
    _startUploader(); // resume uploader if not busy
  }

  // ---------- Private Methods ----------
  void _startUploader() {
    _uploadQueueState.startUploader(
      offlineMode: offlineMode,
      uploadMode: uploadMode,
      getAccessToken: _authState.getAccessToken,
    );
  }

  @override
  void dispose() {
    _authState.removeListener(_onStateChanged);
    _profileState.removeListener(_onStateChanged);
    _sessionState.removeListener(_onStateChanged);
    _settingsState.removeListener(_onStateChanged);
    _uploadQueueState.removeListener(_onStateChanged);
    
    _uploadQueueState.dispose();
    super.dispose();
  }
}